Falling Weight Deflectometer


Structural Evaluation is a proactive study of pavement that enables clients and road owners to produce more realistic and accurate works programs, to better manage resources and to project more accurate budgetary requirements.

By applying a standard load and knowing something about the traffic, we can predict the remaining life in the pavement and hence what needs to be done if traffic patterns are to change or we need rehabilitation or reconstruction.

Pavement Strength Testing

Structural (FWD or HWD) Evaluation could be used as the warning of failure for a section of pavement prior to it being detected visually.

A heavy vehicle bends the pavement introducing some permanent distress into the pavement structure, causing it to fatigue in bitumen and cement bound materials and deform plastically in unbound granular materials, including the subgrade.

The Falling Weight Deflectometer is the world standard dynamic plate bearing test for the non-destructive testing of the structural capacity of flexible pavement and the key to unlocking issues with with concrete slabs. The equipment uses up to nine seismic geophones to measure the deflection of the road pavement under the application of a
known load from a predetermined height.

The pavement response is analysed with industry accepted software to determine the elastic moduli, stresses and strains of each modeled layer.

How FWD works

Heavy Weight Deflectometer

The HWD unit is used for rigid pavements, airports and port authorities. Units are air-portable for movement to and from remote airstrips. It can be set up for assessing concrete slabs, interlocking blocks, in addition to heavy pavements including full depth asphalt.

HWD Load Range: 70 – 240kN

Key Features

  • Characteristics

    • Number of Deflectors: Seven (7)
    • Resolution: 0.001 mm = 1 micron
    • Duration of Test: 35 sec (typ. 3 drops)
    • Max distance from load: (2.1 m)
    • Single person operation
    • Day or night operation
  • Typical use

    • Remaining life of the network
    • Determine the asset value of the network
    • Design, rehabilitation and reconstruction
  • Our Fleet

    • Dynatest – FWD – 016
    • Dynatest – FWD – 161
    • Dynatest – FWD – 402
    • Dynatest – HWD – 043
    • Dynatest – HWD – 100